Some investigations in Talbot interferometry for collimation testing

We have proposed new type of self referncing dual field gratings based on arcs of circles and used them in Talbot interferometer for collimation testing. The performance of these gratings is compared with dual field linear gratings. The difference in sensitivity of arc gratings is verified by simulated moiré fringes. The use of a single self referencing grating with a right angle prism retro reflector in a Talbot interferometer is also discussed.